U.S. patent application number 10/655130 was filed with the patent office on 2004-03-11 for synergistic control of pests.
This patent application is currently assigned to Solvay Fluor und Derivate GmbH. Invention is credited to Baeumert, Klaus, Belt, Heinz-Joachim.
Application Number | 20040047914 10/655130 |
Document ID | / |
Family ID | 7676377 |
Filed Date | 2004-03-11 |
United States Patent
Application |
20040047914 |
Kind Code |
A1 |
Baeumert, Klaus ; et
al. |
March 11, 2004 |
Synergistic control of pests
Abstract
Sulfuryl fluoride and ovicidal gases have been found to exert a
synergistic action on insect eggs, so it is possible to fumigate
under sublethal conditions relative to the ovicide, and the dose of
ovicidal gas can be reduced e.g. to sublethal concentrations.
Inventors: |
Baeumert, Klaus; (Frankfurt
am Main, DE) ; Belt, Heinz-Joachim; (Burgwedel,
DE) |
Correspondence
Address: |
CROWELL & MORING LLP
INTELLECTUAL PROPERTY GROUP
P.O. BOX 14300
WASHINGTON
DC
20044-4300
US
|
Assignee: |
Solvay Fluor und Derivate
GmbH
Hannover
DE
|
Family ID: |
7676377 |
Appl. No.: |
10/655130 |
Filed: |
September 5, 2003 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10655130 |
Sep 5, 2003 |
|
|
|
PCT/EP02/02222 |
Mar 1, 2002 |
|
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Current U.S.
Class: |
424/607 ;
424/703 |
Current CPC
Class: |
A01N 2300/00 20130101;
A01N 59/24 20130101; A01N 59/26 20130101; A01N 59/04 20130101; A01N
37/02 20130101; A01N 37/34 20130101; A01N 47/46 20130101; A01N
29/00 20130101; A01N 25/18 20130101; A01N 59/10 20130101; A01N
59/10 20130101; A01N 59/10 20130101 |
Class at
Publication: |
424/607 ;
424/703 |
International
Class: |
A01N 059/24; A01N
059/02 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 6, 2001 |
DE |
101 10 570.3 |
Claims
What is claimed is:
1. A method of fumigating a room or an object attacked by pests,
said method comprising exposing the room or object simultaneously
to sulfuryl fluoride and an ovicidal gas comprising hydrocyanic
acid, wherein the sulfuryl fluoride and the ovicidal gas are used
under sublethal conditions, and wherein the hydrocyanic acid is
present in a concentration of at most 3 g/m.sup.3.
2. A method according to claim 1, wherein sulfuryl fluoride and
hydrocyanic acid are both used in concentrations which individually
are sublethal with respect to extermination of insect eggs.
3. A method according to claim 1, wherein the ovicidal gas is used
in a concentration which corresponds to at most 70% of the lethal
concentration.
4. A method according to claim 1, wherein the sulfuryl fluoride is
used in a concentration which corresponds to at most 90% of the
lethal dose with respect to larvae, pupae or adults.
5. A method according to claim 1, wherein hydrocyanic acid is used
in a concentration of at most 2.5 g/m.sup.3.
6. A method according to claim 5, wherein hydrocyanic acid is used
in a concentration of at most 2 g/m.sup.3.
7. An ovicidal gas mixture comprising sulfuryl fluoride and
hydrocyanic acid, with the proviso that at most 4 parts by weight
hydrocyanic acid are contained therein per 20 parts by weight
sulfuryl fluoride.
8. A mixture according to claim 7, further comprising carbon
dioxide or a warning gas.
9. A mixture according to claim 7, comprising at most 3 parts by
weight of hydrocyanic acid per 20 parts by weight sulfuryl
fluoride.
10. A mixture according to claim 9, comprising at most 2.5 parts by
weight of hydrocyanic acid per 20 parts by weight sulfuryl
fluoride.
11. A mixture according to claim 10, comprising at most 2 parts by
weight of hydrocyanic acid per 20 parts by weight sulfuryl
fluoride.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of international patent
appliction no. PCT/EP02/02222, filed Mar. 1, 2002, designating the
United States of America, and published in German as WO 02 074089,
the entire disclosure of which is incorporated herein by reference.
Priority is claimed based on Federal Republic of Germany patent
application no. DE 101 10 570.3, filed Mar. 6, 2001.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to a method of pest control
using a synergistically acting combination of gases.
[0003] It is known to use sulfuryl fluoride as a pesticide, see
U.S. Pat. No. 2,875,127. The gas is suitable for controlling pests
and fungi in wood used or not used in buildings, and also in
freshly felled wood, for controlling beetles or termites, and for
pest control in museums, churches, storage rooms or for example
mill buildings. As is known from the publication by E. E. Kenaga in
J. Econ. Entomol. 50 (1957) pages 1 to 6, a very high concentration
of sulfuryl fluoride is necessary to control insect eggs. It has
therefore already been proposed to combine sulfuryl fluoride with
an ovicidal gas (German published application no. DE 197 09 914).
Suitable ovicides include, for example, hydrocyanic acid, alkyl
formates, alkyl isothiocyanates, nitrites, carbonyl sulfide or
hydrogen phosphide.
SUMMARY OF THE INVENTION
[0004] It is an object of the present invention to devise an
improved method by means of which reliable control of pests is
possible. This object is achieved by the method and the mixture of
substances with which reliable fumigation is possible, as described
in further detail hereinafter.
[0005] The method according to the invention for reliable
fumigation of rooms or objects attacked by pests simultaneously
with sulfuryl fluoride and an ovicidal gas provides for sulfuryl
fluoride and the ovicidal gas to be used under conditions which for
sulfuryl fluoride and the ovicidal gas considered on their own are
sublethal with respect to the extermination of insect eggs.
[0006] The term "reliable fumigation" means that all the life
stages of the pests (eggs, larvae, pupae or adults) found in the
rooms or objects attacked by the pests are substantially completely
exterminated.
[0007] It is known to the person skilled in the art that the lethal
dose with respect to insects is determined particularly by the
following factors: the type of the insect; its stage of
development; the concentration of the fumigation agent; the
temperature; the duration of fumigation (see on this point also E.
E. Kenaga, J. Econ. Entomol. 54(1961), pages 537-542). The longer
the fumigation can last, and the higher the temperature at which
the fumigation is carried out, the lower is the lethal
concentration of the fumigation agent. The lethal concentration can
be determined by tests as described by Kenaga. In practical
application, however, it frequently has to be considered that there
is an upper limit to the temperature, because corresponding energy
costs make a great difference or sensitive objects must not be
heated to too high a temperature. The duration of the fumigation
may be limited for economic reasons. The minimum concentration for
achieving an ovicidal action is regarded as 5 g/m.sup.3 for
hydrocyanic acid (HCN, hydrogen cyanide); see German published
application nos. DE 197 32 575 and DE 197 09 914. A minimum
concentration of 20 g/m.sup.3 is quoted for methyl formate, 5
g/m.sup.3 for carbonyl sulfide, 10 g/m.sup.3 for acetonitrile, 5
g/m.sup.3 for methyl isothiocyanate and 50 ppm for hydrogen
phosphide (see German published application no. DE 197 09 914).
[0008] The method according to the invention provides that the
ovicidal gas can be used under conditions which are sublethal with
respect to the substantially complete extermination of the insect
eggs. It is therefore possible to fumigate using a sublethal
concentration of the ovicide, for example at a concentration which
is at most 90%, preferably at most 80% and in particular at most
70% of the concentrations of the ovicidal agent which are lethal
under the given conditions with respect to exterminating eggs.
Alternatively or additionally, it is possible to reduce the
fumigation time and/or to fumigate at a lower temperature.
Preferably fumigation is carried out using sulfuryl fluoride and
the ovicidal gas in concentrations which on their own are sublethal
with respect to the extermination of insect eggs.
[0009] Preferred ovicidal gases include hydrocyanic acid, PH.sub.3,
alkyl formates, alkyl nitrites, alkyl isothiocyanates, carbonyl
sulfide or methyl bromide. "Alkyl" here preferably stands for
methyl or ethyl, in particular methyl.
[0010] The sulfuryl fluoride is used in a concentration which is
lethal to developed stages of the insect (larva, pupa or adult).
Such concentrations are sublethal with respect to the extermination
of insect eggs. The concentrations of sulfuryl fluoride may however
also be reduced somewhat, for example to at most 90% or even less
of the concentration needed to exterminate the larvae, pupae or
adults.
[0011] If different types of insect are being controlled, the
concentrations relate to the insect which is most difficult to
control.
[0012] The preferred ovicidal gas is hydrocyanic acid. Preferably
the hydrocyanic acid is used in a concentration of at most 3
g/m.sup.3, in particular at most 2.5 g/m.sup.3, very particularly
preferably in a concentration of at most 2 g/m.sup.3.
[0013] The method according to the invention is carried out under
conventional conditions. The temperature is advantageously in the
range of 15 to 55.degree. C. The duration of fumigation lies in the
range of about 2 to about 136 hours. The rooms to be fumigated are
advantageously sealed off or enveloped. Carbon dioxide may
additionally be used because it has an advantageous effect on the
effectiveness of fumigation agents.
[0014] For example vehicles, transport vehicles (ships, railway
trucks, lorries), rooms in buildings (churches, museums, mills),
storage rooms (grain stores, silos, bunkers or containers) and also
individual enveloped objects such as works of art can be
treated.
[0015] Advantageously, the water content in the air in the rooms to
be treated is reduced, for example with commercially available
dehumidifiers.
[0016] Sulfuryl fluoride and ovicidal gas may be used in a mixture
or separately. The weight ratios of sulfuryl fluoride to the
preferred ovicidal gases are compiled in the following table, the
particulars each relating to 20 parts by weight sulfuryl
fluoride.
1TABLE 1 Maximum use of ovicidal gas in parts by weight, relative
to 20 parts by weight SO.sub.2F.sub.2. Hydrocyanic Methyl Methyl
Carbonyl acid formate isothiocyanate sulfide Maximum 4 16 4 4
Preferred 3 12 3 3 maximum Particularly 2.5 10 2.5 2.5 preferred
maximum in particular 2 8 2 2 maximum
[0017] The numbers quoted relate to the use of only one type of
ovicidal gas. If a mixture is used, the particulars must be reduced
corresponding to the content of the mixture. A 50:50 mixture of
hydrocyanic acid and methyl formate will then be used in such a
quantity that at most 2 parts by weight hydrocyanic acid and at
most 8 parts by weight methyl formate are used per 20 parts by
weight sulfuryl fluoride.
[0018] The invention also relates to mixtures which comprise or
consist of sulfuryl fluoride and an ovicidal gas selected from the
group consisting of hydrocyanic acid, methyl or ethyl formate,
methyl isothiocyanate or carbonyl sulfide. In this case, the
proviso applies that, if only one type of ovicidal gas is contained
in the mixture, at most 4 parts by weight hydrocyanic acid,
carbonyl sulfide or methyl isothiocyanate and at most 16 parts by
weight methyl or ethyl formate are contained per 20 parts by weight
sulfuryl fluoride. If two or more types of ovicidal gas are
contained in a mixture, the proportion of the respective type of
gas will be reduced correspondingly. For example, if hydrocyanic
acid and methyl formate are contained in the same proportions by
weight, at most 2 parts by weight hydrocyanic acid and at most 8
parts by weight methyl formate are contained in the mixture per 20
parts by weight sulfuryl fluoride.
[0019] The mixtures according to the invention may additionally
contain auxiliaries such as carbon dioxide or warning gases. If the
ovicidal gas is hydrocyanic acid, carbonyl sulfide or methyl
isothiocyanate, mixtures in which at most 3 parts by weight,
preferably at most 2.5 parts by weight, particularly preferably at
most 2 parts by weight, of the ovicidal gas are contained per 20
parts by weight sulfuryl fluoride are preferred. In the case of
alkyl formates, preferably at most 12 parts by weight are contained
therein. For mixtures, what is stated above applies by analogy.
[0020] Preferred mixtures comprise SO.sub.2F.sub.2 and hydrocyanic
acid as the ovicidal gas.
[0021] The invention has the advantage that it is possible to
fumigate unter sublethal conditions with respect to the ovicidal
gas. This means that it is possible to effect reliable
extermination of the pests including any eggs present more quickly,
with a lower gas concentration and/or at a lower temperature.
[0022] The following example is intended to explain the invention
further, without limiting its scope.
EXAMPLES
Example
Fumigation with SO.sub.2F.sub.2/HCN Mixtures
[0023] General:
[0024] 1. Insects Used
[0025] For each concentration batch and the untreated batches, 30
granary weevils Sitophilus granarius on wheat, granary weevil brood
1 (1 week old), 50 eggs of the Mediterranean flour moth Ephestia
kuehniella and 30 red flour beetles Tribolium castaneum and brood
mixture were used. The insects were caged in gauze tubes.
[0026] 2. Time and Duration of the Fumigation
[0027] Each sample batch was fumigated for 48 hours at room
temperature. Then the samples were placed in an atmosphere at
25.degree. C. and 65-70% rel. humidity and monitored for 12
weeks.
[0028] 3. Performance of the Tests
[0029] The samples were introduced into 2.5-liter gas washing
bottles with a septum attachment. Then the corresponding quantity
of gas was injected using a gas syringe. The gas was uniformly
distributed in the bottles by means of a magnetic stirrer. After
the injection, the bottles were allowed to stand for 48 hours.
After aeration, the samples were placed in a climatic chamber and
monitored weekly for further progeny.
[0030] 4. Results
[0031] Both for the batch with 20 g SO.sub.2F.sub.2/m.sup.3 and for
the batch with 1.5 g HCN/m.sup.3, offspring were produced, whereas
for the batch with the combination of 20 g SO.sub.2F.sub.2 and 1.5
g HCN/m.sup.3 no offspring were produced. This corresponds to a
mortality of 100%. The control samples developed normally.
2TABLE 2 Representation of the offspring in the fumigation test
Tribolium Stophilus castaneum 30 Ephestia granarius (30 Sitophilus
live beetles and kuehniella live beetles on granarius brood (50
eggs) cereal) (broodmixture) Sample Sample Sample Sample Dose No.
Offspr. No. Offspr. No. Offspr. No. Offspr. SO.sub.2F.sub.2 + HCN 1
0 4 0 7 0 10 0 20 g/m.sup.3 1.5 2 0 5 0 8 0 11 0 g/m.sup.3 3 0 6 0
9 0 12 0 (according to the invention) Control: SO.sub.2F.sub.2 1a 3
beetles 4a 0 7a 1 beetle.sup. 10a 0 20 g/m.sup.3 2a 4 beetles 5a 0
8a 2 beetles 11a 0 3a 5 beetles 6a 0 9a 9 beetles 12a 0 HCN 1b 9
beetles 4b 0 7b 7 beetles 10b 0 1.5/m.sup.3 2b 8 beetles 5b 0 8b 5
beetles 1b 2 beetles 3b 1 beetle.sup. 6b 0 9b 11 beetles 12b 2
beetles Untreated U1 40 beetles U3 23 moths U5 46 beetles U7 67
beetles U2 40 beetles U4 34 moths U6 25 beetles U8 74 beetles
[0032] The foregoing description and examples have been set forth
merely to illustrate the invention and are not intended to be
limiting. Since modifications of the described embodiments
incorporating the spirit and substance of the invention may occur
to persons skilled in the art, the invention should be construed
broadly to include all variations within the scope of the appended
claims and equivalents thereof.
* * * * *